Still bleeding some after birth control and antibiotics?

I was put on Nitrofuratoin for a UTI about a month ago and am on the birth control pill Dasetta 1/35, after I finished the antibiotic I bled for about 1.5 weeks and into my inactive week. The last day I bled was about a week or two ago, but the last two days I've had some spotting - very sparse but present. Is that normal?

Added 13 Apr 2015:

I am mostly curious if perhaps I am having "breakthrough" bleeding again because my body is adjusting to being on BC again without antibiotics interfering.

The first day or so of my antibiotics we didn't use a condom but he pulled out well before he came and we ended up using a condom to finish. Then a few days after that, when I finished the last day of the antibiotic, I started bleeding and bled into the inactive week (which I assume means I'm not pregnant) and we have used condoms every time since then to be safe and I've continued taking my BCP. :-) The spotting yesterday and today was like a regular period and then pinky today.